Contribution of Gamma-Aminobutyric Amino Acid and Free Amino Acids to Low-Salt Whole-Wheat Bread through the Addition of Spice Extracts—An Approach Based on Taste Quality

Given the link between excessive salt consumption and hypertension, reducing salt levels in bread, an important staple food in Japan, is essential. γ-Aminobutyric acid (GABA) has a salty taste-enhancing effect in vivo, and its production is influenced by the type of spice extract in vitro. However, the effects of spices on GABA levels, total free amino acid composition, and taste quality in whole-wheat bread remain unclear. Therefore, this study aimed to investigate whether the addition of spice extracts, which do not affect bread flavor and taste, can increase the GABA level in low-salt whole-wheat bread and whether free amino acid content affects the taste quality of bread using an automatic home bread maker. Through free amino acid composition analysis and sensory testing, we evaluated the influence of six spice extracts on the composition of free amino acids, including GABA, in whole-wheat bread. We found that cumin and anise extracts were effective in increasing the GABA level to approximately twice that in whole-wheat bread. Moreover, both the preference and saltiness of the bread were favorable, indicating that these extracts are useful for reducing the salt content of whole-wheat bread. This study provides a theoretical basis for guiding industrial production.